Field
This application relates generally to a plug insert for a fastener hole in a panel.
Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 1.98
During the process of constructing an aircraft wing, a panel may be laid up over a previously-added skin panel. Once added, the overlaying “boot” panel covers fastener holes drilled in the skin panel, so matching holes must be drilled in the boot panel to enable fastener installation.
The overlay panel must therefore undergo a divot removal process, i.e., the removal of a portion of an overlay panel from a skin panel to uncover a fastener hole in the main panel. In other words, a small disk-shaped or annular aperture is made in the boot panel over a fastener hole in an aircraft skin panel to which the boot panel has been glued or otherwise adhered.
A common known divot removal process may include the following steps. A metal drill bushing is first placed in a fastener hole in an aircraft skin panel. An outer surface of the drill bushing is then masked, and a primer coat of paint is sprayed over an outer surface of the skin panel and the masked outer surface of the drill bushing. The masking is removed from the drill bushing and a boot panel is glued over the outer surface of the skin panel and the outer surface of the drill bushing. A pilot hole is back-drilled in the boot panel through a cylindrical axial cavity formed axially through the drill bushing. A boot cutter nose is then inserted into the pilot hole from the front or outer side and the cutter is advanced axially until circumferentially-disposed teeth of the boot cutter engage and cut a ring in the boot panel slightly larger in diameter than the front surface of the drill bushing and precisely concentric with the pilot hole.
The resulting annular boot panel divot is then removed from the outer surface of the drill bushing, and the drill bushing is removed so that a fastener can be inserted into the fastener hole.
Some fasteners, such as Dzus® quarter-turn fasteners, include metal sleeve portions shaped to complement the fastener holes. Such sleeve portions, when present, are installed in the fastener holes before the drill bushings are installed so that the drill bushings, once installed, are carried by and concentrically within the pre-installed metal sleeve portions of the fasteners.